/* ===== CSS 变量 ===== */
:root {
    --color-primary: #1a3a6b;
    --color-primary-light: #2a5290;
    --color-primary-dark: #0f2545;
    --color-accent: #c9a961;
    --color-bg: #f5f7fa;
    --color-white: #ffffff;
    --color-text: #2c3e50;
    --color-text-light: #6c7a89;
    --color-border: #e0e6ed;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
    --radius: 12px;
    --max-width: 1200px;
}

/* ===== 基础重置 ===== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial,
        sans-serif;
    color: var(--color-text);
    line-height: 1.8;
    background-color: var(--color-white);
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ===== 通用容器 ===== */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 100px 0;
}

/* ===== 板块标题 ===== */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-accent);
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 12px;
}

.section-title {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--color-primary-dark);
    letter-spacing: 1px;
}

.section-divider {
    width: 60px;
    height: 4px;
    background: var(--color-primary);
    margin: 20px auto 0;
    border-radius: 2px;
}

.section-desc {
    margin-top: 20px;
    color: var(--color-text-light);
    font-size: 1.05rem;
}

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.nav-logo-img {
    height: 40px;
    width: auto;
}

.nav-logo-text {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--color-primary);
    letter-spacing: 1px;
}

.nav-list {
    display: flex;
    gap: 8px;
}

.nav-link {
    display: block;
    padding: 8px 20px;
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text);
    border-radius: 6px;
    position: relative;
}

.nav-link::after {
    content: "";
    position: absolute;
    bottom: 4px;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transform: translateX(-50%);
    transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 60%;
}

/* 汉堡菜单按钮 */
.hamburger {
    display: none;
    flex-direction: column;
    justify-content: space-around;
    width: 32px;
    height: 32px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1001;
}

.hamburger-line {
    width: 100%;
    height: 3px;
    background: var(--color-primary);
    border-radius: 2px;
    transition: var(--transition);
    transform-origin: center;
}

.hamburger.active .hamburger-line:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

.hamburger.active .hamburger-line:nth-child(2) {
    opacity: 0;
}

.hamburger.active .hamburger-line:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* ===== Hero 首屏 ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 50%, var(--color-primary-light) 100%);
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(201, 169, 97, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(42, 82, 144, 0.3) 0%, transparent 50%);
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.hero-content {
    position: relative;
    z-index: 2;
    padding: 0 24px;
    animation: fadeInUp 1s ease-out;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--color-white);
    letter-spacing: 3px;
    margin-bottom: 24px;
    text-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.85);
    max-width: 600px;
    margin: 0 auto 40px;
    line-height: 1.8;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 14px 40px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 50px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    letter-spacing: 1px;
}

.btn-primary {
    background: var(--color-white);
    color: var(--color-primary);
    border-color: var(--color-white);
}

.btn-primary:hover {
    background: transparent;
    color: var(--color-white);
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

/* 滚动提示 */
.hero-scroll-hint {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.scroll-arrow {
    display: block;
    width: 24px;
    height: 40px;
    border: 2px solid rgba(255, 255, 255, 0.5);
    border-radius: 12px;
    position: relative;
}

.scroll-arrow::after {
    content: "";
    position: absolute;
    top: 8px;
    left: 50%;
    width: 4px;
    height: 8px;
    background: rgba(255, 255, 255, 0.7);
    border-radius: 2px;
    transform: translateX(-50%);
    animation: scrollDown 1.8s infinite;
}

/* ===== 关于我们 ===== */
.about {
    background: var(--color-white);
}

.about-content {
    display: flex;
    gap: 60px;
    align-items: center;
}

.about-text {
    flex: 1;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 1.05rem;
    color: var(--color-text-light);
    line-height: 2;
}

.about-text p:last-child {
    margin-bottom: 0;
}

.about-stats {
    flex: 0 0 auto;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.stat-item {
    text-align: center;
    padding: 32px 24px;
    background: var(--color-bg);
    border-radius: var(--radius);
    transition: var(--transition);
}

.stat-item:hover {
    background: var(--color-primary);
    transform: translateY(-6px);
    box-shadow: var(--shadow-md);
}

.stat-item:hover .stat-number,
.stat-item:hover .stat-label {
    color: var(--color-white);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--color-primary);
    line-height: 1.2;
    transition: var(--transition);
}

.stat-number span {
    font-size: 1.4rem;
}

.stat-label {
    margin-top: 8px;
    font-size: 0.95rem;
    color: var(--color-text-light);
    transition: var(--transition);
}

/* ===== 服务内容 ===== */
.services {
    background: var(--color-bg);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.service-card {
    background: var(--color-white);
    padding: 48px 32px;
    border-radius: var(--radius);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border-top: 4px solid transparent;
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
    border-top-color: var(--color-primary);
}

.service-icon {
    width: 72px;
    height: 72px;
    margin: 0 auto 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    border-radius: 20px;
    color: var(--color-white);
    transition: var(--transition);
}

.service-icon svg {
    width: 36px;
    height: 36px;
}

.service-card:hover .service-icon {
    transform: scale(1.1) rotate(5deg);
}

.service-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--color-primary-dark);
    margin-bottom: 16px;
}

.service-desc {
    font-size: 0.95rem;
    color: var(--color-text-light);
    line-height: 1.8;
}

/* ===== 优势特点 ===== */
.advantages {
    background: linear-gradient(180deg, var(--color-white) 0%, var(--color-bg) 100%);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.advantage-item {
    text-align: center;
    padding: 40px 20px;
    position: relative;
    transition: var(--transition);
}

.advantage-item::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 3px;
    background: var(--color-accent);
    transform: translateX(-50%);
    transition: width 0.4s ease;
}

.advantage-item:hover::after {
    width: 70%;
}

.advantage-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 3px solid var(--color-primary);
    border-radius: 50%;
    color: var(--color-primary);
    transition: var(--transition);
}

.advantage-icon svg {
    width: 36px;
    height: 36px;
}

.advantage-item:hover .advantage-icon {
    background: var(--color-primary);
    color: var(--color-white);
    transform: translateY(-5px);
}

.advantage-title {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-primary-dark);
    margin-bottom: 12px;
}

.advantage-desc {
    font-size: 0.92rem;
    color: var(--color-text-light);
    line-height: 1.7;
}

/* ===== 联系我们 ===== */
.contact {
    background: var(--color-white);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.contact-card {
    text-align: center;
    padding: 48px 24px;
    background: var(--color-bg);
    border-radius: var(--radius);
    transition: var(--transition);
    border: 1px solid var(--color-border);
}

.contact-card:hover {
    background: var(--color-primary);
    transform: translateY(-8px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary);
}

.contact-card:hover .contact-icon {
    background: rgba(255, 255, 255, 0.15);
    color: var(--color-white);
}

.contact-card:hover .contact-label,
.contact-card:hover .contact-value {
    color: var(--color-white);
}

.contact-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary);
    border-radius: 50%;
    color: var(--color-white);
    transition: var(--transition);
}

.contact-icon svg {
    width: 28px;
    height: 28px;
}

.contact-label {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-primary-dark);
    margin-bottom: 12px;
    transition: var(--transition);
}

.contact-value {
    font-size: 0.95rem;
    color: var(--color-text-light);
    line-height: 1.8;
    transition: var(--transition);
}

/* ===== 页脚 ===== */
.footer {
    background: var(--color-primary-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: 60px 0 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    padding-bottom: 40px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.footer-logo {
    max-width: 120px;
    height: auto;
    object-fit: contain;
}

.footer-desc {
    font-size: 0.92rem;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.65);
}

.footer-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-white);
    margin-bottom: 20px;
}

.footer-links ul li {
    margin-bottom: 12px;
}

.footer-links ul li a {
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.65);
}

.footer-links ul li a:hover {
    color: var(--color-accent);
    padding-left: 6px;
}

.footer-contact p {
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.65);
    margin-bottom: 12px;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 24px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.88rem;
    color: rgba(255, 255, 255, 0.5);
}

/* ===== 回到顶部按钮 ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    border: none;
    border-radius: 50%;
    background: var(--color-primary);
    color: var(--color-white);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
}

.back-to-top svg {
    width: 22px;
    height: 22px;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--color-accent);
    transform: translateY(-4px);
}

/* ===== 淡入动画 ===== */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 错开动画延迟 */
.services-grid .service-card:nth-child(2).reveal,
.advantages-grid .advantage-item:nth-child(2).reveal,
.contact-grid .contact-card:nth-child(2).reveal {
    transition-delay: 0.15s;
}

.services-grid .service-card:nth-child(3).reveal,
.advantages-grid .advantage-item:nth-child(3).reveal,
.contact-grid .contact-card:nth-child(3).reveal {
    transition-delay: 0.3s;
}

.services-grid .service-card:nth-child(4).reveal,
.advantages-grid .advantage-item:nth-child(4).reveal,
.contact-grid .contact-card:nth-child(4).reveal {
    transition-delay: 0.45s;
}

.services-grid .service-card:nth-child(5).reveal,
.contact-grid .contact-card:nth-child(5).reveal {
    transition-delay: 0.6s;
}

.services-grid .service-card:nth-child(6).reveal,
.contact-grid .contact-card:nth-child(6).reveal {
    transition-delay: 0.75s;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes scrollDown {
    0% {
        opacity: 1;
        transform: translate(-50%, 0);
    }
    100% {
        opacity: 0;
        transform: translate(-50%, 16px);
    }
}

/* ===== 响应式 - 平板 ===== */
@media (max-width: 992px) {
    .section {
        padding: 80px 0;
    }

    .hero-title {
        font-size: 2.8rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .about-content {
        flex-direction: column;
        gap: 40px;
    }

    .about-stats {
        width: 100%;
        grid-template-columns: repeat(4, 1fr);
    }

    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .contact-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
    }

    .footer-brand {
        grid-column: 1 / -1;
    }
}

/* ===== 响应式 - 手机 ===== */
@media (max-width: 768px) {
    .section {
        padding: 60px 0;
    }

    .container {
        padding: 0 20px;
    }

    .nav-container {
        height: 64px;
    }

    .nav-logo-text {
        font-size: 1.1rem;
    }

    .nav-logo-img {
        height: 34px;
    }

    /* 汉堡菜单 */
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        height: 0;
        background: var(--color-white);
        overflow: hidden;
        box-shadow: var(--shadow-md);
        transition: height 0.4s ease;
    }

    .nav-menu.active {
        height: calc(100vh - 64px);
        overflow-y: auto;
    }

    .nav-list {
        flex-direction: column;
        gap: 0;
        padding: 20px 0;
    }

    .nav-list li {
        border-bottom: 1px solid var(--color-border);
    }

    .nav-link {
        display: block;
        padding: 16px 24px;
        font-size: 1.05rem;
        border-radius: 0;
    }

    .nav-link::after {
        display: none;
    }

    /* Hero */
    .hero-title {
        font-size: 2rem;
        letter-spacing: 1px;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .btn {
        padding: 12px 32px;
    }

    /* 关于我们 */
    .about-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }

    .stat-item {
        padding: 24px 16px;
    }

    .stat-number {
        font-size: 2rem;
    }

    /* 服务 */
    .services-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .service-card {
        padding: 36px 24px;
    }

    /* 优势 */
    .advantages-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    /* 联系 */
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .contact-card {
        padding: 36px 20px;
    }

    /* 页脚 */
    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .footer-bottom p {
        font-size: 0.82rem;
    }

    /* 回到顶部 */
    .back-to-top {
        width: 42px;
        height: 42px;
        bottom: 20px;
        right: 20px;
    }
}

/* ===== 响应式 - 小屏手机 ===== */
@media (max-width: 480px) {
    .hero-title {
        font-size: 1.6rem;
    }

    .hero-subtitle {
        font-size: 0.9rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .section-tag {
        font-size: 0.8rem;
    }

    .about-stats {
        grid-template-columns: 1fr;
    }

    .stat-item {
        padding: 20px 16px;
    }
}